Submission #131107

#	Time	Username	Problem	Language	Result	Execution time	Memory
131107		mlyean00	Cave (IOI13_cave)	C++14	100 / 100	416 ms	640 KiB

cave

#include <bits/stdc++.h>
#include "cave.h"

using namespace std;

const int MAX = 5000;
int n;

bool sure[MAX];
// Correct position of switch (such that the door is open)
int pos[MAX];
// Door the switch is connected to
int door[MAX];

// Find the switch to door d
void find_switch(int d, bool b) {
    int lo = 0;
    int hi = n;
    while (lo < hi) {
        int t[n];
        copy(pos, pos + n, t);

        int mid = (lo + hi) / 2;
        for (int i = lo; i <= mid; ++i) {
            if (!sure[i]) t[i] = 1;
        }

        int res = tryCombination(t);

        if (b ^ (res == -1 || res > d)) {
            hi = mid;
        } else {
            lo = mid + 1;
        }
    }

    door[lo] = d;
    sure[lo] = true;
    pos[lo] = !b;
}

void exploreCave(int N) {
    n = N;

    for (int i = 0; i < n; ++i) {
        int cur = tryCombination(pos);
        find_switch(i, cur == -1 || cur > i);
    }

    answer(pos, door);
}

• Subtask 1: 12 / 12
• Subtask 2: 13 / 13
• Subtask 3: 21 / 21
• Subtask 4: 30 / 30
• Subtask 5: 24 / 24